A blown deadline isn’t an automatic bar to habeas review for an inmate who shows actual innocence of the crime, the U.S. Supreme Court has ruled.

In a 5-4 opinion (PDF), the court said a missed deadline isn’t an absolute bar to review, but “unjustified delay” does count against the inmate. “Our opinion clarifies that a federal habeas court, faced with an actual-innocence gateway claim, should count unjustifiable delay on a habeas petitioner’s part, not as an absolute barrier to relief, but as a factor in determining whether actual innocence has been reliably shown,” Justice Ruth Bader Ginsburg wrote for the majority.

The deadline for habeas review is set by the Antiterrorism and Effective Death Penalty Act of 1996. Ginsburg said an inmate may be excused from the time limit when it is “more likely than not that no reasonable juror would have convicted him in the light of the new evidence.” Unexplained delay in bringing forward new evidence bears on the determination.

The court ruled in the case of Michigan inmate Floyd Perkins, convicted of the 1993 murder of an acquaintance after a party in Flint. Perkins filed his habeas petition claiming ineffective assistance of counsel more than 11 years after his conviction became final. He relied on three witness affidavits pointing to another man at the party as the actual killer.

A federal court had originally ruled that the evidence in the affidavits was “substantially available” at trial and denied Perkins’ petition. The Cincinnati-based 6th U.S. Circuit Court of Appeals reversed, saying the actual innocence claim allowed Perkins to pursue his habeas petition. The Supreme Court remanded to the district court and said its appraisal of Perkins’ ability to meet the actual-innocence standard “should be dispositive, absent cause, which we do not currently see, for the 6th Circuit to upset that evaluation.”

Justice Antonin Scalia dissented in an opinion joined by Chief Justice John G. Roberts Jr. and Clarence Thomas, and partly joined by Justice Samuel A. Alito Jr. “The Constitution vests legislative power only in Congress, which never enacted the exception the court creates today,” Scalia wrote. “Judicially amending a validly enacted statute in this way is a flagrant breach of the separation of powers.”

Scalia said the majority had “its eye firmly fixed on something it likes—a shiny new exception to a statute unloved in the best circles.” The decision today “piles yet more dead weight onto a postconviction habeas system already creaking at its rusted joints,” he wrote.